Wavefront coding is a set of specialized aspheric optics, detection and signal processing. In the prior art, the signal processing is dictated by the aspheric optics such that the spatial blur caused by wavefront coding is removed. The aspheric optics “code” the wavefront so that the sampled image is relatively insensitive to misfocus-related aberrations. The intermediate image from the coded wavefront (i.e., the image sampled by the detector) is not sharp and clear. Signal processing processes data from the detector to remove the spatial blur caused by the aspheric optics, to “decode” wavefront coding.
By way of example, FIG. 1 shows one prior art wavefront coded optical imaging system 100. System 100 includes optics 101 and a wavefront coded aspheric optical element 110 that cooperate to form an intermediate image at a detector 120. Element 110 operates to code the wavefront within system 100. A data stream 125 from detector 120 is processed by image processing section 140 to decode the wavefront and produce a final image 141. A digital filter (a “filter kernel”) 130 is implemented by image processing section 140. Filter kernel 130 consists of filter taps, or “weights,” that are real or integer values with a maximum dynamic range due to the limits of processing hardware and software, for example 128-bit extended floating-point arithmetic, real number mathematics, and scaling/truncation of integer values. Scaling may for example include general series of partial products computations and accumulations.
In the prior art, optical element 110 and detector 120 do not necessarily match the available processing capability of image processing section 140; accordingly, image degradation may be noted within final image 141. If optical element 110 and detector 120 are matched to the available processing capability, it may require a very complex and costly hardware implementation in terms of detector capability, optical design of element 110, and/or computer processing architectures associated with image processing section 140.